A scalable piezoelectric impulse-excited generator for random low frequency excitation

This paper introduces an impulse excited piezoelectric energy harvesting prototype. The device is aimed at large amplitude, low frequency excitation typical of human body motion. A rolling, external proof mass actuates an array of piezoelectric cantilevers that form a distributed transduction mechanism. After initial deflection, the beams vibrate at their natural frequency. This allows for improved electromechanical coupling and large operational bandwidth. Measurements are presented to include different excitations and proof masses and an IC for voltage regulation is evaluated. At an excitation frequency of 2 Hz and an acceleration of 2.72 m/s² a power output of 2.1 mW was achieved.